859: Attack of the glycines!
|Name:||859: Attack of the glycines!|
|Expired:||03/20/2014 - 23:59|
|Description:||Glycine is an unusual amino acid. Of the 20 standard amino acids, it is the only one that does not have handedness: all others cannot be superimposed on their mirror images, but glycine can. This means that glycine is just as happy forming one structure -- (an ordinary, right-handed alpha-helix, for example) as it is forming the mirror image structure (a backwards, left-handed helix, for example). This extra flexibility and the competition with other, energetically equivalent states makes it hard to lock glycine in one conformation, meaning that glycine tends to disrupt secondary structure.
As a special, extra-hard challenge, we're asking you to try to design a protein that is able to fold, with the restriction that every set of 9 residues has a stretch of 3 glycines in it. This means that regions of secondary structure are likely to be very short. We will be testing top designs with our structure-prediction algorithms. The usual rules apply: we want well-packed, void-free, hydrophobic cores and nice, polar surfaces. Good luck!
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